Means for regulating electric circuits.



lATENTED MAR. 28, 1805.

.W. S. MOODY MEANS FOR REGULATING ELECTRIC CIRCUITS.

' APPLICATION FILED JULY 26. 1902 2 SHEETS-SHEET l.

Inventor.

Walter S. TTloodg. 9m.

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No. 785,970. PATENTED MAR. 28, 1905.

w. s. MOODY. MEANS FOR REGULATING ELECTRIC CIRCUITS.

APPLICATION FILED JULY 26, 1902.

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Inventor. Walter S. Mood g.

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UNITED STATES Patented March 28, 1905.

PATENT OEEIcE.

WALTER MOODY, OF SCHENECTADY, NE'W YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MEANS FOR REGULATING ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 785,970, dated March 28, 19 05.

Application filed July 26, 1902. Serial No. 117,099. I

To all whom it may concern.-

Be it known that I, WALTER S. MOODY, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Means for Regulating Electric Circuits, of which the following is a specification.

My present invention comprises certain improvements in regulating apparatus particularly useful for varying the voltage of current delivered by alternating-current transformers.

The invention, although designed more particularly with a View to the regulation of apparatus of the character mentioned, possesses, however, various features capable of useful application in numerous other relations. Consequently I do not wish my invention confined to the particular apparatus which I have hereinafter described in connection with the accompanying drawings, but rather to be construed as to its features of novelty by reference to the appended claims.

In practice occasion frequently arises for varying the voltage of current supplied by alternating-current transformers. This may of course be accomplished by varying the ratio of transformation of the transformer or by the use of an induction-regulator, both of which are recognized methods of accomplishing the desired result. In some instances, however, they possess disadvantages either as to cost of construction or difficulties of operation such as to render them undesirable. I have found that the result aimed at may be secured through the use of a boosting or auxiliary transformer, the primary of which is supplied with a variable voltage and is located in inductive relation to leads or terminals extending from the main transformer, which leads or terminals constitute the secondary of the boosting-transformer. By varying the voltage impressed upon the primary of the boosting-transformer, and thereby as a consequence varying the magnetomotive force of the primary, I produce by induction a corresponding regulating voltage in the leads of former.

the main transformer. Depending upon the polarity of the current which is sent through the primary of the regulating-transformer, this regulating voltage may either add itself to the voltage of the main transformer or counteract a portion of the voltage of the same, thereby permitting a variation of voltage of the apparatus as a whole through a considerable range of operation.

In the drawings, Figure l is a sectional View of an apparatus embodying my invention, Fig. 2 a plan view, and Fig. 3 a perspective view of the same apparatus minus the transformer case or tank shown in Fig. 1.

Fig. 4is a simplified diagram of circuits of the apparatus.

In Fig. 1 the main transformer occupies the central position of the view and may be of any usual or well-known construction. As shown, it consists of a magnetic core formed in two portions, each in the form of a shell, one surrounding one of the legs of the transformer-winding and the other the other leg. One of these shells is indicated in cross-section at l and the companion shell at 2. The lower shell surrounds the lower horizontal portions of a series of windings constituting the primary and secondary coils, one of which windings is indicated at 3. The upper shell 2 surrounds the upper horizontal portions of these windings, as will be readily seen. The active portions of the windings are therefore entirely surrounded by the iron core, which is built up of laminae in the usual manner.

The winding indicated at 3 is one of a number of flat tape-covered or otherwise insulated coils which together constitute the primary or high potential winding of the translnterspersed with these coils, constituting the high-potential winding, are arranged the tubular conductors, such as 4, constituting the low potential winding. This low-potential winding, which has, however, relatively few turns as compared to the highpotential winding, is formed of tubes of cop per or other good conducting material, so as to permit a circulation of cooling fluid to be maintained in the winding for the purpose of conducting away heat generated in the transformer, thereby preventing undue rise in temperature of the apparatus. The tubular conductors forming the low-potential winding of the transformer are extended upward and are arranged so that the leads or extensions of like polarity are arranged in one row and those of the opposite polarity in another row, these rows being shown for convenient inspection at 5-and 6, respectively, in Fig. 3. The terminals as thus arranged permit the turns or coils corresponding thereto to be readily connected in series with each other, in multiple, or in any other manner desired, as will be evident to one skilled in the art.

In order to vary the voltage of current delivered by the transformer, I mount a pri mary inducing-Winding in inductive relation to the leads or extensions of the low-potential winding already described, the active portions of the inducing-winding and of the leads of the main transformer being surrounded with magnetic material to reduce the reluctance of the paths traversed by th magnetic fluxes.

The relative arrangement of the inducing and induced members of the regulating or booster-transformer thus constituted is perhaps indicated best in Fig. 2, in which the upwardly-extending leads of the main transformer are shown at 7 for example, and the interspersed primary or inducing-windings in plan view at 8. A core of laminated iron is arranged so that the middle leg or portion extends through the middle of the inducingwinding between the two sets of leads of the main transformer, as will be seen clearly at 9, Fig. 1. The two outside legs of the magnetic circuit (shown in section at 10 and 11) are connected together at their ends and to the middle leg by end portions, as at12 in Fig. 3. The fluxes set up by the action of the primary inducing winding traverse the middle leg of the magnetic circuit, then divide and flow back through the two outside legs, thereby completing its circuit. The action of the magnetic fluxes induced by the primary or regulating winding is to set up or induce an electromotive force in the several leads going to makeup the sets of terminals 5 6. In order to enable the electromotive force thus set upto be varied, I provide means for varying the electromotive force impressed upon the exciting or primary winding of the regulatingtransformer. For this purposeI connect the primary winding of the regulating transformer, through a circuit-changing switch,(in dieated in diagram in Fig. 4,) to selected points in the high-potential winding of the main transformer. By varying the connections I may raise or lower the voltage impressed upon the primary of the regulating-transformer and may reverse its direction at will.

In the diagram shown in Fig. 4 the highpotential winding of the main transformer is represented at 13 and its low-potential winding at 14. For convenience this low-potential winding is represented as a single winding; but it is to be understood that in practice it may be built up of a plurality of separate portions, which may be connected in series with each other or in multiple or in any other desired way, so as to enable a change in the ratio of transformation to be made when desired. Such change would, however, ordinarily not be made while the apparatus was in operation.

To vary the voltage while the apparatus is in operation, I make use of the regulating or boosting transformer already described, the primary of which is indicated in the diagram at 15. This primary is shown adjacent the leads extending from the winding 14 and as thus shown is intended to represent an inductive relation between the leads and the winding. Inasmuch as the leads are merely straight tubes and have no turns, the illustration in the diagram will be readily understood. Oneterminal of the primary 15 is connected to an intermediate point, such as 16, of the highpotential winding 13, and the other terminal to a switch-arm 17, adapted to move over a row of contacts connected to a series of taps from the winding 13, some lying on one side and some on the other of the tap connected to the winding. By placing the switch on contacts on one side of the middle contact 16 current may be made to flow in one direction through the primary 15, and by placing it on the other side the direction of current may be reversed, the voltage of the current passed through the winding 15 being determined in either instance by the amount of winding comprised between the middle tap 16 and the tap to which the switch-arm 17 happens to be connected.

In actual construction of the apparatus thus described there are certain mechanical features to which reference has not hitherto been made. Thus, for example, it will be noted that the regulating-transformer is supported in position by means of brackets 18 19, bolted to one of the clamping-plates 20 of the core of the main transformer.

At 21 in Fig. 3 will be seen a re in'esentation of a coil of piping. This coil. is intended to be traversed by cooling fluid, such as water, for the purpose of cooling the oil or other insulating fluid in which the apparatus is immersed and to which heat generated in the apparatus is communicated by contact therewith. This coil is for convenience of illustration omitted from the view shown in Fig. 1.

In order to furnish a convenient means for placing the apparatus in the containing-casing 22 and to remove it therefrom when desired, I provide a heavy lifting-bar 23, me chanically connected to upwardly-projccting bosses 24, formed integral with the clamping members 20 and 25, between which the iron core of the main transformer is secured. This lifting bar or member 23 has a downwardlyextending portion 26, which projects nearly into contact with the core of the transformer, so as to form two openings 27, through which convenient engagement maybe made with suitable hoisting apparatus.

Fig. 1, being a sectional view, shows some only of the various leads of the apparatus necessary to effect the connections indicated in the diagram in Fig. 4:. These leads extend out to a switching mechanism which it has not been considered necessary to illustrate in detail, sufficient information being furnished to one skilled in the art by the diagram in Fig. 4.

What I claim as new, and desire to secure by Letters Patent of the United States, is

l. The combination of a main transformer, an auxiliary transformer arranged so that one of its current-carrying members includes incoming and outgoing leads of one of the windings of the main transformer, and means for varying the current in the other member of the auxiliary transformer.

2. The combination of a main transformer, an auxiliary transformer arranged so that its secondary member forms a continuation of .incoming and outgoing leads of the secondary member of the main transformer, and means forsupplying the primary of the auxiliary transformer with current Variable in amount and reversible in polarity.

around said leads, and a primary winding carried by said core in inductive relation to said leads.

5. The combination of a transformer havinglow-potential and high-potential windings, leads extending from the low-potential winding, acore of magnetic material located around said leads, a primary winding carried by said core in inductive relation to said leads, and means for supplying said primary winding with current of variable voltage.

6. The combination of a transformer having high-potential and low-potential windings, a plurality of pairs of leads extending from the low-potential winding and constituting terminals of portions of said winding whereby the said portions may be connected in series or in multiple or otherwise as desired, a core of magnetic material arranged in proximity to said terminals or leads, and an inducing-winding on said core in inductive relation to said leads.

7. The combination of a transformer having a winding formed of portions the interconnection of which may be varied, leads for said portions, and means for inducing in said leads a regulating electromotive force or electromotive forces.

8. The combination of a transformer having a magnetic core upon which are mounted high-potential and low potential windings, terminals or extensions for one of said windings, acore of magnetic material arranged in proximity to said terminals or extensions and mechanically supported by the structure of the transformer, and a regulating winding in inductive relation to said terminals or extensions.

In witness whereof I have hereunto set my hand this 25th day of July, 1902.

\VALTER S. MOODY.

Witnesses:

BENJAMIN B. HULL, MARGARET E. XVOOLLEY. 

